Streaming songs from iTunes library when library is disconnected (external hard drive)

[YLP]

Hello,

I use an external hard drive for my iTunes library. Now when I'm on the go, I sometimes want to listen on Spotify to some albums I have in my iTunes library, but Spotify seems to want to play them exclusively from the iTunes library, and thus won't stream them, so I can't listen to them. Any solution to this other than disconnecting Spotify from my library ?

I'm using Mac OSX 10.8.3 and latest Spotify Premium.

Thanks.